Air strainer



March 25, 1941. L s 2,236,273

AIR STRAINER Filed Feb. 15, 1939 Fig.1

INVENTOR RICHARD l NASH ATTORNEY Patented Mar. 25, 1941 UNITED STATESAIR STRAINER- Richard L. Nash, Franklin, Pa., asslgnor to TheWestinghouse Air Brake Company,-Wilmer.ding, Pa., a corporation ofPennsylvania Application February 15, 1939, Serial No. 256,410

2 Claims.

This invention relates to air strainers, and more particularly to thetype of strainer adapted for use in conjunction with internal combustionengines and fluid compressors.

Fluid strainers of the type to be hereinafter more specificallydescribed are subjected to operation under widely varying conditions.The continued successful operation of the engine or compressor to whichthe strainer is applied is frequently dependent upon the condition andefliciency of the strainer. Therefore, improved means have been providedin the present device to insure long periods of elficient operation byproviding an oil bath type strainer arranged to produce progressivecleaning of the air passed therethrough and which at the sametime haslarge capacity for collecting coarse or heavy dirt.

It is highly desirable that strainers of this type be adapted to beeasily assembled and taken apart so as to facilitate the removal,inspection, cleaning, renewal and replacement of the dirt collectingmediums without necessitating the dismantling of any pipe connections.

A principal object of the present invention is to provide an improvedair strainer of the oil bath type with large dirt retaining capacity.

Another object of the present invention is to provide an oil bath typesuction strainer which provides for progressive cleaning of the airpassed therethrough and which may readily be assembled and taken apart.

Other objects and advantages will appear from the following descriptionof an illustrative embodiment of the present invention.

In the accompanying drawing, Fig. 1 is a vertical sectional view of anair strainer constructed in accordance with the teachings of the presentinvention; Fig. 2 is a horizontal sectional view taken on the line 2-2of Fig. 1.

As shown in Fig. l of the drawing, the air cleaning device comprises acasing having a cup shaped portion l and a cover 2, and furthercomprises an air strainer portion 3 and a dirt collecting portion 4,both of which portions are enclosed by the casing.

The dirt collecting portion 4 is located below the strainer portion 3and may comprise a centrally disposed and vertically extending tubularmember 5, having an annular flange 6 at its lower end which rests on thebottom inner wall of the casing portion l. Welded or otherwise securedto the exterior vertical surface of the tubular member are a pluralityof spaced radially extending and vertically disposed dirt collectingplates 1. Resting on the upper edge of these plates, and secured theretoby welding or otherwise, is a horizontal pan or plate 8 which dividesthe interior of the'casing linto .a chamber 9 adapted to contain aquantity of liquid'and an air inlet chamber 10. This plate is generallyoi shallow cup shape and is of such diameter that anupstanding.peripheral flange it forms an annular passage 12 between the outersurface of the flange H and the interior wall of the casing I, Ill. Thechambers are also connected by a plurality of peripherally spacedopenings IS in the plate 8. This plate also has a raised central portionI which is provided with a central opening I5, which communicates withthe space between the radially spaced plates 1 and the bottom wall ofthe casing l.

The chamber 9 is adapted to contain a quantity of suitable liquid, suchas oil, the normal level of which is. determined by a visible groove l6which extends around the interior wall of the casing l.

The strainer portion 3 may comprise a cylindrical center portion l1having at one end an outwardly projecting annular flange l8 and atthe'opposite end an inwardly projecting annular flange I9, forming'atthis end a central aperture 20. The flange I9 is welded or otherwiseattached to the upper face of the raised central. portion I4 of the 'panor plate 8, so that the aperture 20 is in, alignment with the opening15.

A screen wire or other foraminated section 2| is disposed in the casingI! which at its periphery is welded or otherwise secured to the sidewall in spaced relation to the inner surface of the annular flange 19,thus forming between this surface and the section 21 a chamber 22.

The open end of the center cylindrical portion IT is closed by a screenwire or other foraminated member 23 having an annular flange 24 which isadapted. to engage the peripheral surface 25 of'the portion H. The upperedge of this flange extends to the top surface of the flange it, asshown in Fig. 1 of the drawing.

A quantity of suitable straining material 26 such as hair, felt,shredded metal or glass wool is disposed in the space between theforaminated'sections 2| and 23.

The cover portion 2 has a raised central portion 21 which rests on thestrainer portion 3 andis held securely'in place by wing nuts 28.Thesewing nuts en age'the cover and are adapted to make screwthreaded'engagement with bolts 29, the threaded end of which projects throughholes 30 peripherally spaced in the cover 2. The bolts29 are attachedvattheir opposite ends as by rivets 3|, .to the outer edge at the open endof the .cup shaped casing l.

The cover 2 is also provided with a downwardly projecting annular flange32 of such diameter that an annular passage 33 isformed between the.innersurface-oi this flange and the outersu-rface orthe cunt-shaped prtion This passage'connects; chamber with the atmoswhich connects thechambers 9 and phere, thereby providing an air inlet passage to thecleaning device.

A sealing gasket 34 is interposed between the raised central portion 21of the cover 2 and the strainer portion 3, as shown, thus forming anoutlet chamber between the foraminated section 23 and the cover.

The gasket 34 prevents leakage between the inlet chamber II] and theoutlet chamber 35 and also holds the foraminated section 23 in positionwhen compressed upon tightening the wing nuts 28.

For the purpose of connecting the cleaning device to the suction inletof a device, such as a fluid compressor, a pipe boss 31 is welded orotherwise attached to the top of the raised central portion 2! of thecover portion 2. The boss 31 is provided with a pipe threaded centralopening 38 which aligns with an outlet opening 36 in the cover abovechamber 35.

Assuming an installation on a railway vehicle in normal operation of theair strainer device, due to vibration, the oil in chamber 9 will besplashed over the radially projecting surfaces of the dirt collectingplates! and over the underside of the horizontal pan or plate 8. The oilwill also pass through the openings I3 to the upper surface of thisplate, so that these surfaces as well as a portion of the side Wall ofcasing I above the normal oil level will become oil moist. However, itmight be mentioned here that the pan and dirt collecting plates preventexcessive splashing of oil, which might otherwise 7 x be splashed out ofthe strainer.

Fluid passing from the atmosphere through the strainer device, enters byway of annular inlet passage 33 and flows to inlet chamber H], fromwhich it passes by Way of passage l2 to chamber 9. In flowing fromchamber l0 over and in contact with the upstanding peripheral flange IIto chamber 9 any heavy particles of foreign matter in the air will beremoved by falling into the shallow cup shaped pan or plate 8 and willadhere to the oil moist surfaces. Other particles of foreign matter willalso adhere to the oil moist surfaces of passage [2 and the underside ofplate 8 in chamber 9.

The partially purified air in chamber 9 then passes through the spacesbetween the dirt collecting plates 1 where other foreign particles inthe air will be removed, the smaller particles adhering to the oil moistsurfaces of the dirt collecting plates while the larger particles willfall into the oil.

The movement of oil due to vehicle movement will more or lesscontinually wash the collected dirt off the radially spaced dirtcollecting plates and from the underside of the plate or pan 8.

From the spaces between the radially spaced plates 7, air will pass tothe outlet passage 38 by way of opening I5, aperture 20, chamber 22through the straining material 26, chamber 35 and opening 36. In passingthrough the straining material 25 the remaining fine particles of dirtwill be removed.

As will now be evident, the air straining device provided by thisinvention is constructed in such a manner that it is capable ofcollecting large quantities of coarse or heavy dirt without becomingclogged, which will obviously prolong the effective life of the strainerbetween cleaning periods.

The strainer device is best cleaned by first dismantling it. This may'be done by unscrewing the wing nuts 28 upon which the cup shapedportion containing the strainer and dirt collecting portions 3 and 4 isreadily separated from the cover 2. The connected strainer and dirtcollecting portions 3 and 4 are then removed from the cup shaped portionI, after which the straining material 26 and the oil in chamber 9 may beremoved.

While one embodiment of the cleaning device provided by this inventionhas been illustrated and described in detail it should be understoodthat the invention is not limited to these details of construction andthat numerous changes and modifications may be made without departingfrom the scope of the following claims.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In an air cleaning device, in combination, a casing having an inletpassage, an outlet passage and a liquid containing sump at the bottomthereof, means in the form of a pan adapted to be kept moist with liquidfrom said sump and disposed in said casing above the static level ofliquid in the sump and forming therebetween an air chamber andcomprising an upstanding annular flange which together with the easingdefines an air duct therebetween through which incoming air may flow tosaid chamber, said flange being constructed and arranged to direct theflow of at least part of the incoming air across the surface of the panbefore it flows through said duct, a plurality of radially spaced platesdisposed in said chamber and extending into said sump and also beingadapted to be kept moist with liquid from said sump, a fibrous strainingmedium disposed in a chamber above said pan and in advance of saidoutlet passage, said pan, plates and straining medium being so arrangedas to cause air entering said inlet passage to first flow at least inpart across the surface of said pan and to then flow in a single annularpath through said duct to the chamber between the liquid level and theunder side of said pan and then in a plurality of paths between saidplates and finally in a single path upwardly through and in contact withsaid fibrous straining medium to said outlet passage.

2. In an air cleaning device, in combination, a casing having an inletpassage, an outlet passage and a liquid containing sump at the bottomthereof, means in the form of a horizontal pan adapted to be kept moistwith a liquid medium and having a centrally disposed aperture, said panbeing of sufiicient size to substantially separate said sump from theupper region of the casing and being so disposed in said casing abovethe static level of liquid in said sump as to form an air chambertherebetween, a fibrous air straining medium disposed in said casingintermediate said pan and the top of said casing and in communicationwith said aperture, a plurality of radially spaced plates also adaptedto be kept moist with liquid from said sump and located below said panand extending into said sump, said pan, plates and fibrous medium beingso disposed in said casing as to cause air entering said inlet passageto first flow in a single annular path over and in contact with said panto the chamber between the liquid level in the sump and the bottom ofthe pan, then in a plurality of paths between and in contact with saidplates, then in a single vertical path through said aperture, andfinally in a single path through and in contact with said strainingmedium to said outlet passage.

' RICHARD L. NASH.

